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Can you correct nulls with acoustic treatments.

I have Magnepan 1.6's. After hearing a musical clarity I really liked in a listening session at someone else's house, I broke down and bought a Rat Shack SPL meter and dowloaded some test files. I wanted to see if it was the acoustics or the type of speakers and system that made the difference.

A brief testing showed a 65 to 80 hz., 5 or 6 db. bump (the drywall bump?) that I had expected. What I didn't expect was 10 to 15 hz. wide nulls (-10,-15,even -20 db.) at several other frequencies.

I tried moving speaker positioning and the frequency of the nulls moved but the pattern was basically the same.

Acoustic treatment to tame + nodes seems intuitive. Can you treat nulls or is this a different problem?

Would really appreciate your thoughts.

Jim S.

stilljd
myraj
351 posts
 
You can't/it's difficult to correct for nulls/dips except with placement. The best placement will always have peaks and dips, except with perfect placement in a perfect room
All one can do is smooth out the peaks, With treatment, or with EQ. It difficult to impossible to correct for the nulls, unless you are using EQ with active crossovers.
Good luck!
audiooracle
387 posts
 

You have to understand the nature of nulls, meaning that a null is a depression in frequency response due to cancellation effects based on room interaction.

A null can not be tuned out by passive attenuation which is what room treatments can accomplish. You must redirect the energy by repositioning or by adding more bass energy to compensate for the null.
captain
81 posts
 
good morning, have you tried THE RULE OF THIRDS for your speaker placement?
acoustat6
357 posts
 
Thats the whole idea. Well part of it anyway. To reduce standing waves (peaks and nulls), along with modal ringing, which is just as important. To absorb or diffuse sound in the room to avoid ringing and flutter echoes, and improve stereo imaging. This is some of the things that acoustic treatment helps with and which EQ cannot. Now about those acoustic resonators....
Bob
samujohn's avatar
samujohn
291 posts
 
Hi Jim,
Welcome to the wonderful world of measurements. Its seems to me that you have two basic choices.
1. Move your speakers and listening position about until you get the best subjective results and then stop. Trust me, few do better.
2. Get serious about measuring and the post your results so others can coach you through the process of taking measurements and interpreting them. Expect a serious learning curve. You may eventually opt for room correction, but you should be properly informed before spending. New speakers may be far cheaper - or may do nothing to correct the problem. I went for a Tact unit and a sub with my dipoles. I am happy with the results, but it took a while.
regards,
Sam
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